A device for comminuting, in particular, softer materials such as, coal or the like, the device including at least two vertically spaced, superposed grates disposed in the outlet region of a bunker and equipped with crushing elements of which at least one grate is stationary and at least one further grate is movable translatorily in the horizontal direction relative to the stationary grate.
DE-B 1,167,163 (German Auslegeschrift/laid-open application) discloses a vibrating screen crusher whose vibrating box is equipped with a striking grate at the bottom and is covered at the top, at least in part, by an impact plate. The material passes through this vibrating box in the longitudinal direction and the box is caused to vibrate in the vertical plane by means of two crankshafts equipped with counterbalancing means. The crankshafts are disposed underneath the vibrating box. The impact plate as well as the striking grate are provided with facing crushing teeth. At the vibrating box, in the region of the last third of the impact plate, breaker hammers are pivotally mounted at pivot arms. By way of pneumatic springs the pivot arms are supported at the vibrating box.
DE-C 650,461 discloses a comminutor for coke, coal, and similar substances that includes a crushing machine equipped with picks and a vibratory table carried by longitudinal rods on which the material to be comminuted moves along the vibratory table is being caused to move in a way that produces shaking jolts of a magnitude that corresponds throughout to the size of the pieces brought underneath the various groups of picks.
The drawbacks of these two devices are essentially that the masses to be handled may produce damage to the grates and to the peripheral components due to the superposition of vibrations. In both cases, the passage of the comminuted material is essentially horizontal with no high throughputs being possible due to the materials to be processed.
Additionally, DE-B 1,223,235 discloses a breaker grate for the discharge of a reaction furnace, wherein the grate is formed of a fixed grate composed of parallel grate rods having sharp-edged raised portions and of a movable grate. The movable grate is formed by a frame which includes transverse connecting rods disposed between the raised portions of the fixed grate rods and equipped with breaker heads that cooperate with the grate rods.
The drawbacks of this prior art device are essentially that in this arrangement, certain size categories can no longer be drawn in and broken up but roll along only on the edges of the breaker heads insofar as the dimensions of the grain are larger than the amount of lateral shift of the grate. Since the grains are generally not pre-sorted before they are charged onto the grate, the danger exists here of overloading the system since larger chunks clog the intake region. The efficiency of such a system can thus be considered to be relatively low.